Understanding how brain damage affects visual attention

Top-Down Attentional Control of Visual-Processing

This study is testing how brain damage affects the way people pay attention to what they see by comparing those with brain injuries to healthy volunteers.

Quick facts

• Study type: Observational
• Enrollment: 300 (estimated)
• Ages: 18 Years to 100 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (NIH)
• Drugs / interventions: Radiation
• Locations: 1 site (Bethesda, Maryland)
• Trial ID: NCT01087281 on ClinicalTrials.gov

What this trial studies

This study aims to investigate how individuals with focal brain lesions process visual information compared to healthy volunteers. Participants will undergo a series of behavioral tasks and functional magnetic resonance imaging (fMRI) to assess the role of different brain regions in attentional control. The research will focus on the contributions of the prefrontal and parietal cortices in modulating visual processing. By comparing the performance of patients with brain damage to that of neurologically healthy individuals, the study seeks to enhance our understanding of attentional mechanisms in the brain.

Who should consider this trial

Good fit: Ideal candidates include individuals aged 18 and older with unilateral or bilateral focal lesions in specific brain areas, at least three months post-injury.

Not a fit: Patients with neurological or psychiatric disorders unrelated to the focal lesions, or those with recent substance abuse issues, may not benefit from this study.

Why it matters

Potential benefit: If successful, this research could lead to improved strategies for rehabilitation and treatment of attention-related deficits in patients with brain injuries.

How similar studies have performed: Previous studies have shown promising results in understanding attentional processes in patients with brain lesions, suggesting that this approach is grounded in established research.

Eligibility criteria

* INCLUSION CRITERIA:

All Subjects

1. All subjects will be 18 years of age or older and have at least a high school education.
2. Capacity to provide their own informed consent, understand and cooperate with study procedures.
3. Able to read and write in English to guarantee understanding of all written and spoken instructions, which are in English.

Patients:

1. Unilateral or bilateral focal lesions of prefrontal, parietal, occipital or temporal cortex, or amygdala.
2. At least three months post-stroke, lobectomy and or neurosurgical resection.

Healthy volunteers:

1\. Neurologically normal and in good general health.

EXCLUSION CRITERIA

Patients:

1. Any neurological or psychiatric disorder not related to the focal lesion (e.g., epilepsy, schizophrenia, etc.). Epilepsy patients who have undergone surgery and as a result are seizure free may be recruited.
2. Previous head injury.
3. Present or past (within past 6 months) drug or alcohol abuse or addiction as determined by a qualified study neurologist/psychiatrist.
4. Radiation treatment to the brain during a three-month period prior to the experiment.

Healthy volunteers:

1. Any neurological or psychiatric disorder (e.g., epilepsy, schizophrenia, etc.)
2. Previous head injury.
3. Present or past (within past 6 months) drug or alcohol abuse or addiction based on DSM-5 criteria as determined during History and Physical exam.

ADDITIONAL EXCLUSION CRITERIA FOR MRI SCAN:

Patients and Healthy volunteers:

1. Women who are pregnant and women of child-bearing potential who refuse to undergo a urine pregnancy test will be excluded from fMRI experiments.
2. Subjects who have contraindications to MRI scanning will be excluded from fMRI experiments but included in cognitive experiments. These contraindications include:

   1. central nervous system aneurysm clips;
   2. implanted neural stimulator;
   3. implanted cardiac pacemaker or defibrillator;
   4. cochlear implant;
   5. ocular foreign body (e.g., metal shavings);
   6. insulin pump;
   7. metal shrapnel or bullet;
   8. any implanted device that is incompatible with MRI.
3. Conditions that preclude scanning, e.g., morbid obesity, claustrophobia.

ADDITIONAL EXCLUSION CRITERIA FOR TASKS INVOLVING COLOR DISCRIMINATION:

Patients and Healthy volunteers:

Subjects who are determined during screening or history and physical exam to be color-blind will be excluded from participating in certain tasks that involve color discrimination.

Where this trial is running

Bethesda, Maryland

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States (Recruiting)

Study contacts

• Principal investigator: Shruti A Japee, Ph.D. — National Institute of Mental Health (NIMH)
• Study coordinator: NIMH LBC Volunteer

Conditions Focal Brain Lesion; Focal Lesions; fMRI; Visual Attention; Visual Cortex; Neurological Disorder; Functional Magnetic Resonance Imaging; Natural History